Method and apparatus for the negative reproduction of masters on a copy bearer utilizing a heat absorbing layer



Feb. 4, 1964 E. LIND 3,120,611

METHOD AND APPARATUS FOR THE NEGATIVEREPRODUCTION 0F MASTERS ON A COPYBEARER UTILIZING A HEAT ABSORBING LAYER Filed May 6, 1960 INVENTOR.

B ERWIN LIND United States Patent METHOD AND APPARATUS FOR THE NEGATIVEREPRODUCTIQN 0F MASTERS ON A (IOIY HEARER UTILIZING A HEAT ABSORBINGLAYER Erwin Lind, Wiesbaden-Biebrich, Germany, assignor to KalleAktiengesellsclraft, Wiesbaden-Biebrich, Germany, a corporation ofGermany Filed May 6, 1960, Ser. No. 27,431 Claims priority, applicationGermany May 15, 1959 25 Claims. (Cl. 250-65) The present inventionrelates to negative reproduction of masters on a copy bearer by the useof heat and more particularly to the transfer of an image to relativelyinexpensive paper.

Heretofore it has been known that copies can be produced if a master isbrought into intimate contact with a reproduction material consisting ofa thin paper having on one side a pigmented wax covering as reproductioncoating. The master is placed on the paper side of the reproductionmaterial and a paper, which is later to carry the copy (the copybearer), on the wax side. If, after the material has been thus set up,lreat rays are beamed upon the master, they will be preferentiallyabsorbed in the dark parts of the master and converted into perceptibleheat. This heat flows firstly through the paper of the master and thenthrough the paper of the reproduction material to the wax coating, inwhich it produces melting. In the parts corresponding to the dark partsof the master the wax then becomes transferred to the copy bearer, sothat a copy corresponding to the master is obtained thereon.

\ An object of the present invention is to provide a process andmaterials for making negative copies of masters by the transfer of imageforming material to a copy bearer.

A further object is to provide an inexpensive process and inexpensivematerial for duplicating copies by the passage of heat through a masterand depositing an observable image on inexpensive copy bearer material.

Other objects and advantages will be apparent from the followingdescription.

The present invention includes a process for the preparation of copiesfrom a master by the action of heat by means of a reproduction layerwhich is in contact with a copy bearer characterized in that a heat-raytransmittant, heat-conduction inhibiting intermediate layer, is setbetween master and reproduction coating and heat rays are then passedtherethrough, provision being made by means of heat-absorbing agentsthat the parts of the reproduction layer corresponding to the image-freepartsof the master are preferentially heated so that a negative image.of the master is formed on said copy bearer in contact with thereproduction layer.

The masters used may be of many different kinds. They are normally thin,heat-ray transmittant materials made in particular of cellulose productsor plastics and furnished on one side with a text or drawing. For theheat-ray transmittant, heat-conduction inhibiting intermediate layerthin foils of transparent or opaque (light-diffusing) material can beused provided they adequately transmit heat-rays and are capable ofinhibiting heat-conduction. For example, foils made of celluloseproducts such as paper, cellulose hydnate, cellulose esters such ascellulose acetate, cellulose propionate and cellulose acetobutyrate,various plastics, e.g., polyolefines such as polyethylene,polypropylene, polyvinyl alcohol, polyvinyl chloride and polyvinylidenechloride, polyamides, poly- 3,120,611 Patented Feb. 4, 1964 esters suchas polyterephthalic acid glycol ester, polycarbonates and polyurethanesmay be used. In particular, foils made of cellulose acetate,polyolefines, polyvinylcompounds with chlorine content and polyestersare suitable. It is also possible for thin glass plates to be used butin general flexible foils are to be preferred.

The inhibition or heat-conduction is, among other things, a function ofthe thickness of the layer. Selection of the appropriate thickness forthe heat-ray transmittant heat-conduction inhibiting layer will give therequired effeet. In general, layers of a thickness within the range ofabout 20 to 300p, preferably of about to about ZOO r will be used.Layers of greater thickness only seldom give an improved effect. Layersof less thickness will not adequately inhibit heat conduction, except inspecial cases and under very accurate conditions, so that thin layerswill only very seldom be resorted to.

The reproduction material used consists of a support furnished with areproduction layer.

The support may, for example, consist of thin foils made of celluloseproducts such as paper and cellulose hydrate, cellulose esters such ascellulose acetate and cellulose propionate. Equally well thin foils madeof plastics as detailed in the previous paragraph as suitable for theheat-ray transmittant, heat-conduction inhibiting intermediate layer maybe used. Because of their cheapness and effectiveness the celluloseproducts are in general preferable. The thickness of the support ispreferably from about 20 to about 40 4. Thinner and also thickersupports may be used.

The reproduction layers used are in general ones of which the meltingpoint is between 30 and 140 C., preferably between 50 and C. Thosehaving wax-type properties are preferred. The required properties are ingeneral achieved by a combination of a number of substances. Primarily,natural and synthetic waxes, advantageously so-called hard lwaxes suchas carnauba wax, esparto wax, candelilla wax and mixtures of suchproducts are used. In addition to these hard waxes, the reproductionlayers generally contain substances that increase flexibility anddecrease brittleness. For this purpose, mineral oils or other parafiinhydrocarbons such as petrolatum, ozocerite, ceresin, Vaseline or softparaflins are added. Also, natural and synthetic resins such ascolophon-y, shellac, polystyrene, polyethylenes, polyacrylates, alkylcellulose, dyestuffs, pigments and fillers may be worked into thecoating mixture.

An example of a simple reproduction layer is one consisting of equalparts of carnauba wax and mineral oil into which a d-yestuff is mixed.

The essential characteristics of the reproduction layer comprise amelting point within the required range and a certain wax-likestickiness, enabling the layer to be easily transferred to the copybearer, to which it will then adhere.

It is therefore not absolutely esesntial that the reproduction layersshould consist of or contain a wax in a narrow sense; other naturallyoccurring or synthetic products with wax-like properties, e.g. parafiinshigher fatty acids, higher aliphatic alcohols and higher aliphaticketones, polygly cols, polyethylene oxides, polyglycerine, andsubstitution products such as chloroparaflins can also be used. The expression Wax-type substances used in this invention should comprise allthe naturally occurring waxes and the synthetic waxes and the productswith wax-like properties mentioned above.

The wax-type reproduction layer is applied to the supglass.

porting material in known manner. The material is melted and is appliedto the support by casting, roller application or spraying. For theprevention of curling, the application of a back-coating to the supportis often advisable. For this purpose a thin, non-pigmented, waxtypecoating can, for example, be used.

The substances used as heat-absorbent material are ones that heavilyabsorb heat rays and convert them into perceptible heat. Dark-coloredlayers or layers consisting of dark material, e. g., plastics or paperfoils colored black throughout, are suitable. -Foils to which a blackcoating has been applied are also suitable. Photographic papers or filmswhich have been exposed to light, developed and fixed are thus verysatisfactory.

For preference, however, a dark dyestuff or dark substance such ascarbon-black is added directly to the waxtype reproduction layer and theheat absorption thus effected. The essential thing is for dark-colored,preferably black materials to be brought into intimate contact with thewax-type reproduction layer, either by layer-tolayer contact or by thepresence of the two materials in one layer. The heat-absorbent substancecan with advantage be selected so that it has an absorption maximum inthe wave-length region transmitted by the heat radiator.

Suitable heat radiation sources are ones which have a sufficiently hightemperature, e.g., from some hundreds of degrees to several thousands.In general, commercially available infra-red radiators are used. It isan advantage if the rays are concentrated by means of reflectors on theimage surface. It is advisable for the quantity of heat necessary forthe melting of the reproduction layer to be applied in a brief radiationof high intensity. In this way sharper images are obtained than when thesame quantity of heat is applied by less intensive radiation of longerduration.

Foils of the most varied materials, in particular foils such as alreadydetailed above as suitable material for the heat-transmittant,heat-conduction inhibiting intermediate layer, can be used as thesupporting material for the final copy, i.e., as the copy bearer.However, here too papers and other cellulose products are used forpreference. The copy bearer can also consist of metal foils or Foilsmade of metal such as aluminum, copper or zinc or those made up ofseveral layers of meta-l, e.g., chromium on copper, as used for thepreparation of printing plates, are particularly suitable. In same casesit is possible to use dark colored copy bearers which also serve at thesame time as light absorbent layers.

There are a number of ways in which the present invention can be carriedinto effect.

For example, FIGURE 1 shows a master a with printing on one side whichis placed upon a heat-ray transmittant, heat-conduction inhibitingintermediate layer b and then the two together are placed upon thereproduction material consisting of a support c, e. g., paper, and thewaxtype reproduction layer d. The reproduction material is arranged insuch a way that the reproduction layer d is away from the master. Ablack paper is then placed on the reproduction layer as cop-y bearer fand the heat rays are beamed upon the master thus irradiating thevarious superposed layers. The arrows show the direction of the heatrays used. Due to its black color the copy bearer 1 serves also as heatabsorbing material e. An image is obtained on the copy bearer which is anegative of the master. If a light colored reproduction layer is used,readily legible copies which are light on dark ground are obtained.

'A modification of this procedure (FIG. 1a) consists in the applicationof the reproduction layer d directly to the heat-ray transmittant,heat-conduction inhibiting intermediate layer b. Thus intermediate layerb at the same time serves as support for the reproduction layer d. Forthe reproduction layer to be effective the intermediate layer (b=c) musthave adequate thickness. Thicknesses greater than 20/ p and up to about300/ lb, preferably from 4 about 100 to about 200/ are consideredadequate. Layers of even greater thicknesses can be used but in generalno further improvement of the effect is achieved.

A further procedure (FIG. 2) consists in the placing of a reproductionmaterial consisting of a support 0 and the reproduction layer ddownwards, upon a copy bearer f and in the placing thereon of a materialwhich on the side facing the reproduction material has a dark,powerfully heat-absorbent layer 2, e.g., exposed, developed and fixedphotographic material, as heat-ray transmittant, heat conductioninhibiting layer b. Upon this mtaerial the master a is then placed andthe heat rays beamed thereon.

A particularly effective procedure (FIG. 3) by which the process can becarried out consists in the placing of a reproduction materialconsisting of a support 0 and a reproduction layer d, with itsreproduction layer d against the copy bearer f, the reproduction layerin this case containing a dark dyestuff or a dark pigment such ascarbonblack, as heat-absorbing agent. Therefore the reproduction layerat the same time serves as heat absorbing material e. A heat-raytransm-ittant, heatconduction inhibiting sheet b is placed on thereproduction material, and then the master a is laid on top. Heat raysare then beamed upon the master and in this way the copy is produced onthe copy bearer f.

It is also possible (FIG. 3a) to coat the support c with a heatabsorbing layer 2 and to coat this layer e in turn with a reproductionlayer d instead of incorporating the heat absorbing material into thereproduction layer.

A further (see FIG. 4) simplified modification of the process describedabove (in FIG. 3) consists in the application of the reproduction layerd containing the heatabsorbing agent e directly to the heat-raytransmittant, heat-conduction inhibiting intermediate layer b serving atthe same time as support c. Reproduction material of this type is placedwith the reproduction layer (d c) against the copy bearer f and themaster a is placed on top.

It is also possible not to incorporate the heat absorbing material intothe reproduction layer but to coat both materials in two separate layers(see FIG. 4a).

The procedure described in FIG. 4 is particularly suit able forcontinuous processing. In such case there may, for example, be, in atransparent hollow roller making up the heat-ray transmittant,heat-conduction inhibiting layer, a device which presses the master frominside. The heat radiation source is also in the hollow roller and soalso may be the reflector which concentrates the heat rays on the imagesurface. The reproduction material and the material serving as copybearer are passed over the roller.

The copying process described above enables negative copies to beprepared from masters simply and rationally. The copies keepsatisfactorily at room temperature and if heated to -100 C. can betransferred to another supporting material. Also, if a metal is used ascopy bearer, the parts not covered with the reproduction coating can beetched and in this way printing plates can be produced.

Examples (1) A coating preparation produced by the melting all togetherat a constant speed of several metres a minute.

through the image plane of a focused 1500 watt infra-red radiator.non-absorbent parts of the master and becomes transferred to thetypewriter paper beneath it which is to serve as copy bearer. From anegative master a positive image 1 The reproduction layer becomes hotunder the which at room temperature has very good stability is obtained.

(2) A coating preparation produced by the melting together of 36 partsby weight of carnauba wax, 1 part by weight of ozocerite, 40 parts byweight of mineral oil, 5 parts by weight of oleic acid, 3 parts byweight of crystal Violet and 15 parts by weight of carbon black is castupon a cellulose hydrate foil of a thickness of 100g. The coated foil isexposed under a master to radiant heat as described in Example 1. Thecellulose hydrate foil serving as supporting material for the coatingpreparation acts simultaneously as heat-insulating intermediate layer.

(3) 30 parts by weight of carnauba wax, parts by weight of crude montanwax, 40 parts by weight of mineral oil and 5 parts by weight of SudanRed BK are melted together to form a coating preparation. Thispreparation is coated upon a carbon tissue paper with a weight of 25 g.per square metre. The coated paper is placed coated side upon a copybearer, the opposite side being covered with a photographic film thathas been exposed to light, developed and fixed and which will absorb theheat radiation passing through the original. It is the black side of thefilm that is put in direct contact with the back of the wax-coatedpaper. The acetate film with the silver coating serves simultaneously asheat ray transmittant, heat-insulating intermediate layer. In thecopying process the master is laid on the heat-insulating film. Anegative red image of the master appears on the copy bearer.

(4) An exposed, developed and fixed photographic silver halide film iscoated on its layer side with a melt containing 10 parts by weight ofparafline (melting point 5658 C.) and 1 part by weight of Sudan YellowGG (Color Index, 2nd Edition, Vol. 3, No. 11020). The reproductionmaterial thus produced is placed with its layer side onto a whiteduplicating paper, which serves as the copy bearer, and then brieflyexposed under a master to infra-red radiation. Under the image-freeareas of the master, the yellow coating on the silver halide film meltsand a yellow image is produced on the contacting white duplicatingpaper, which is a negative with regard to the master used.

(5) A carbon tissue paper having a weight of 20 g. per square metre iscoated with a melt made up of 10 parts by weight of a synthetic wax(Gersthofener Wachs KP), 10 parts by weight of parafiine of a meltingpoint of 56-58 C., and 20 parts by weight of castor oil. Further, 6parts by weight of titanium dioxide were added, while stirring, to themelt as pigment. The reproduction material thus obtained is then placedcoated side down on a paper pigmented black throughout which serves asthe copy bearer. Prior to irradiation of the reproduction material withinfra-red rays through a master, there is superimposed on the uncoatedside of the reproduction material an about 100 thick polyvinyl chloridefilm which serves as heat insulating layer and prevents the conductionof heat from the heat-absorbent areas of the master toward thereproduction layer. By this heat treatment, a white image correspondingto the image-free areas of the master is formed on the black coloredpaper.

(6) The melt described in Example 5 is coated onto a 100 1. thickcellulose hydrate film. The film is placed coated side on a papercolored black throughout and, after superimposing a master on theuncoated side of the cellulose hydrate film, the assembly is exposed toa short, intensive infra-red radiation. For this purpose, thereproduction material is passed in close contact over the image plane ofa focused 1375 watt infra-red radiator at a speed of some metres perminute. The cellulose hydrate film used as the support serves also asthe heat-insulating layer and prevents the conduction of heat from theheat-absorbing areas of the master toward the reproduction layer. Theinfra-red radiation passing through the image-free parts of the masteris absorbed by the black paper serving as the copy bearer. Thereproduction layer in contact 6 with the black paper melts in the neatedareas and on the black paper a white image is formed which is a negativeof the master used.

It will thus be seen that applicant has provided an efiicient and simpleprocess of making copies by transferring an image to a copy bearer andit will be apparent that various changes may be made in the applicationof the invention within the valid scope of the appended claims.

What is claimed is:

1. The method of reproduction comprising superimpos ing on a heatabsorbing layer a reproduction layer which is coated on a support andsuperimposing on said support a heat ray transmittant, heat conductioninhibiting layer, applying a master on said heat ray transmittant, heatconduction inhibiting layer and passing heat rays through the mastertoward said heat absorbing layer for forming a negative image of themaster on said heat absorbing layer.

2. The method of reproduction comprising superimposing on a heatabsorbing layer a reproduction layer which is coated on a heat raytransmittant, heat conduction inhibiting layer, applying a master onsaid heat ray transmittant, heat conduction inhibiting layer and passingheat rays through the master toward said heat absorbing layer forproducing a negative image of the master on said heat absorbing layer.

3. The method of reproduction comprising superimposing on a copy bearera reproduction layer which is coated on a support and superimposing onsaid support a heat ray absorbing layer coated on a heat raytransmittant, heat conduction inhibiting layer, applying a master onsaid heat ray transmittant, heat conduction inhibiting layer and passingheat rays through the master toward said copy bearer for producing anegative image of the master on said copy bearer.

4. The method of reproduction comprising superirnposing on a copy bearera dark colored reproduction layer which is coated on support andsuperimposing on said support a heat ray transmittant, heat conductioninhibiting layer, applying a master on said heat ray transmittant, heatconduction inhibiting layer, and passing heat rays through the mastertoward said copy bearer for producing a negative image of the master onsaid copy bearer.

5. The method of reproduction comprising superimposing on a copy bearera reproduction layer which is coated on a heat ray absorbent layer, thelatter in turn being coated on a support, and superimposing on saidsupport a heat ray transmittant, heat conduction inhibiting layer,applying a master on said heat ray transmittant, heat conductioninhibiting layer, and passing heat rays through the master toward saidcopy bearer for producing a negative image of the master on said copybearer.

6. The method of reproduction comprising superimposing on a copy bearera dark colored reproduction layer which is coated on a heat raytransmittant, heat conduction inhibiting layer, applying a master onsaid heat ray transmittant, heat conduction inhibiting layer, andpassing heat rays through the master toward said copy bearer forproducing a negative image of the master on said copy bearer.

7. The method of reproduction comprising superimposing on a copy bearera reproduction layer which is coated on a heat ray absorbing layer, thelatter in turn being coated on a heat ray transmittant, heat conductioninhibiting layer, applying a master on said heat ray transmittant, heatconduction inhibiting layer and passing heat through the master towardsaid copy bearer for producing a negative image of the master on saidcopy bearer.

8. The method of transferring an image to a paper sheet comprisinginterposing a heat ray transmittant, heat conduction inhibiting layerbetween a master and a supported heat absorbent image forming layer andplacing a copy bearer in contact with the image forming layer, wherebyat least a portion of the heat absorbent layer will be transferred tothe copy bearer when heat rays are passed through the master to the copybearer.

9. The method of forming a negative image from a master comprisingapplying the master on a heat ray transmittant, heat conductioninhibiting layer which is in contact with a layer of image forming heatabsorbing material, whereby transmitted heat rays passing through themaster and the heat ray transmittant, heat conduction inhibiting layerwill selectively heat the portions of the image forming layer.

10. A process for the preparation of copies from a master by the actionof heat comprising providing a reproduction layer in contact with a copybearer, positioning a heat ray transmittant, heat conduction inhibitinglayer adjacent the reproduction layer and on the opposite side of suchreproduction layer from the copy bearer, placing a heat absorbing agentclosely adjacent the reproduction layer, placing the master adjacent theheat transmittant heat conduction inhibiting layer, and passing heatrays therethrough so that the heat rays are absorbed by heat absorbingagents closely adjacent the reproduction layer corresponding to the nonimage areas of the master so that a negative image of the master isformed on the copy bearer in contact with the reproduction layer.

11. A process according to claim 10 in which a waxtype reproductionlayer is used.

12. A process for the preparation of copies from a master by the actionof heat comprising providing a reproduction layer in contact with a copybearer, positioning a heat ray transmittant heat conduction inhibitinglayer of a thickness from about to about 300 between the reproductionlayer and the master, providing heat absorbing agent in a layer adjacentthe reproduction layer, which heat absorbing agent serves to absorb heatin such layers, and passing heat rays through said layers therebypreferentially heating the reproduction layer and forming an image inthe negative on said copy bearer.

13. A process for the preparation of negative copies from a master bythe action of heat comprising providing a reproduction layer in contactwith a copy bearer, providing a heat absorbing layer adjacent to saidreproduction layer which will absorb radiant energy to which it isexposed, positioning a heat ray transmittant heat conduction inhibitinglayer closely adjacent the heat absorbing layer and the reproductionlayer and selecting the thickness of such heat ray transmittant heatconduction inhibiting layer so that radiant energy passing through saidlayer will selectively heat the portions of the reproduction layer inthe non-image areas of the master thereby forming a negative image ofthe master.

14. A method of making negative masters from a positive original byradiant heat comprising placing a heat ray transmittant master havingheat absorbent indicia in contact with one surface of a heat raytransmittant heat conduction inhibiting member, positioning a copybearer adjacent the other surface of said heat ray transmittant heatconduction inhibiting member, positioning a heat softenable reproductionlayer between said heat ray transmittant heat conduction inhibitingmember and said copy bearer with the heat softenable reproduction layerin contact with said copy bearer and placing a heat absorbing layerclosely adjacent said heat softenable reproduction layer whereby heatrays originating on the side of said positive original away from saidcopy bearer and away from said heat ray transmittant heat conductioninhibiting member pass through said positive original and said heat raytransmittant heat conduction inhibiting member concentrating heat onsaid heat absorbing layer causing softening of said heat softenablereproduction layer and adherence of the softened portion of said heatsoftenable reproduction layer on said copy bearer whereby a negativeimage of said positive original is produced on said copy bearermaterial.

15. Reproduction materials for making negative copies from the mastercomprising a support, a meltable reproduction layer on said support fordirect contact with a copy bearer, a heat ray transmittant heatconduction inhibiting layer for positioning between a master to becopied and the reproduction layer and a heat absorbent layer on the sideof said heat ray transmittant heat conduction inhibiting layer away fromthe master.

16. The invention according to claim 15 in which the heat absorbentlayer is incorporated in the copy bearer, and the heat ray transmittantheat conduction inhibiting layer is separate from said support layer.

17. The invention according to claim 15 in which the heat absorbentlayer is incorporated in the copy bearer and the support and heat raytransmittant heat conduction inhibiting layer are incorporated in asingle layer.

18. The invention according to claim 15 in which the heat absorbentlayer is mounted on the surface of said heat ray transmittant heatconduction inhibiting layer away from the master, and the heat raytransmittant heat conduction inhibiting layer is separate from thesupport.

19. The invention according to claim 15 in which the heat absorbentlayer is incorporated in the reproduction layer, and the heat raytransmittant heat conduction inhibiting layer is a separate layer fromthe support.

20. The invention according to claim 15 in which the heat absorbentlayer is mounted on the support between the support and the reproductionlayer, and the heat ray transmittant heat conduction inhibiting layer isa separate layer.

21. The invention according to claim 15 in which the support and heatray transmittant heat conduction inhibiting layer are a single layer andthe heat absorbent layer is incorporated in the reproduction layer.

22. The invention according to claim 15 in which the support and heatray transmittant heat conduction inhibiting layer are a single layer andthe heat absorbent layer is mounted between the said single layer whichis the support and the heat ray transmittant heat conduction inhibitinglayer and the reproduction layer.

23. The invention according to claim 22 in which the said single layerwhich is the support and the heat ray transmittant heat conductioninhibiting layer and the heat absorbant layer are an exposed anddeveloped film.

24. A reproduction material for making negative copies from a mastercomprising a support, a heat absorbing layer positioned on said supportwith one surface of said heat absorbing layer mounted on one surface ofsaid support, and a meltable reproduction layer mounted with one surfacethereof on the other surface of said heat absorbing layer whereby onesurface of a heat ray transmittant heat conduction inhibiting layer maybe placed on the other surface of said support, a master placed on theother surface of said heat ray transmittant heat conduction inhibitinglayer, and a copy bearer placed on the other surface of saidreproduction layer, so that heat rays may be passed through the mastertoward said copy bearer heating the non-image areas of the heatabsorbing layer and thereby heating the meltable reproduction layer insaid non-image areas to transfer the reproduction layer in saidnon-image areas to said copy bearer.

25. A reproduction material for making negative copies from a mastercomprising a support, said support providing a heat ray transmittantheat conduction inhibiting layer, a heat absorbing layer mounted withone surface on one surface of said support providing a heat raytransmittant heat conduction inhibiting layer, and a meltablereproduction layer mounted with one of its surfaces on the other surfaceof said heat absorbing layer whereby a master may be placed on the othersurface of said support providing a heat ray transmittant heatconduction inhibiting layer and a copy bearer placed on the othersurface of said reproduction layer and heat rays passed through saidmaster, through said heat ray transmittant heat conduction inhibitinglayer in a direction from said master toward said copy bearer therebyheating the nonimage areas of the heat absorbing layer and the meltablethe reproduction layer in said non-image areas to said copy bearer.

References Cited in the file of this patent UNITED STATES PATENTS Clarket a1. Oct. 21, 1958 10 Miller Apr. 3, 1956 Roshkind Nov. 6, 1956Roshkind Oct. 8, 1957 Miller Mar. 31, 1959 Nieset Dec. 8, '1959Kuhrmeyer et a1 Dec. 29, 1959 Howard Aug. 30, 1960

14. A METHOD OF MAKING NEGATIVE MASTERS FROM A POSITIVE ORIGINAL BYRADIANT HEAT COMPRISING PLACING A HEAT RAY TRANSMITTANT MASTER HAVINGHEAT ADSORBENT INDICIA IN CONTACT WITH ONE SURFACE OF A HEAT RAYTRANSMITTANT HEAT CONDUCTION INHIBITING MEMBER, POSITIONING A COPYBEARER ADJACENT THE OTHER SURFACE OF SAID HEAT RAY TRANSMITTANT HEATCONDUCTION INHIBITING MEMBER, POSITIONING A HEAT SOFTENABLE REPRODUCTIONLAYER BETWEEN SAID HEAT RAY TRANSMITTANT HEAT CONDUCTION INHIBITINGMEMBER AND SID COPY BEARER WITH THE HEAT SOFTENABLE REPRODUCTION LAYERIN CONTACT WITH SAID COPY BEARER AND PLACING A HEAT ABSORBING LAYERCLOSELY ADJACENT SAID HEAT SOFTENABLE REPRODUCTION LAYER WHEREBY HEATRAYS ORIGINATING ON THE SIDE OF SAID POSITIVE ORIGINAL AWAY FROM SAIDCOPY BEARER AND AWAY FROM SAID HEAT RAY TRANSMITTANT HEAT CONDUCTIONINHIBITING MEMBER PASS THROUGH SAID POSITIVE ORIGINAL AND SAID HEAT RAYTRANSMITTANT HEAT CONDUCTION INHIBITING MEMBER CONCENTRATING HEAT ONSAID HEAT ABSORBING LAYER CAUSING SOFTENING OF SAID HEAT SOFTENABLEREPRODUCTION LAYER AND ADHERENCE OF THE SOFTENED PORTION OF SAID HEATSOFTENABLE REPRODUCTION LAYER ON SAID COPY BREARER WHEREBY A NEGATIVEIMAGE OF SAID POSITIVE ORIGINAL IS PRODUCED ON SAID COPY BEARERMATERIAL.